Grant: 22-014R
Project Title: Evaluating the effects of sand characteristics on the incubation environment for loggerhead (Caretta caretta) sea turtles
Project Manager: Kelly Sloan
Organization: Sanibel Captiva Conservation Foundation (Non-Profit Organization)
Grant Amount: $15,120.00
Completion Date: 2023-06-07
Summary: Many of Florida's natural sandy beaches are disappearing due to storm action, rising seas, and human development of the shore that interferes with the natural movement of sediment. Beach nourishment is considered a "soft" measure that can help replace lost sand and is a common response to erosion. Sand placement is generally viewed as less harmful to sea turtles than armoring, but it is well documented that it can affect sea turtle reproductive success in a variety of adverse ways. Beach renourishment has been occurring on Captiva Island since 1961, with the most recent project starting in August, 2021. Last season (2021) SCCF launched a project evaluating the effects of sand particle size, color, bulk density, and compaction on nest temperature, moisture, and groundwater influence. The relationship of these variables with hatch/emergence rates will also be assessed. Preliminary analyses suggest that there are significantly different sand grain sizes on Sanibel and Captiva, and these varying sediment characteristics may impact rate of water flow and temperature within the nest chamber, possibly resulting in decreased emergence success. This project will support funding for staff time to continue the project in 2022 to better characterize these influences over multiple seasons considering that the nesting environment is dynamic and subject to seasonal fluctuations in storms, predators, and other losses.
Results: During this reporting period, the technician time was spent downloading, entering, and processing data. Our database for this project is massive and compiling the data and getting it into a usable format is quite time consuming. Our grant funded technician accepted a new position in November 2022, and after November 4 the PI wrapped up all technician related duties. We are requesting compensation for 17 hours of PI time at $15/hr, the approved hourly rate for this grant. Between the technician and the PI, the hours spent in this reporting period have allowed us to successfully organize the dataset and begin statistical analysis for this project.